In most cases the neighbor-joining (NJ) tree showed
shallow intraspecific and deep interspecific divergence.
However, in one exceptional case there was a deep divergence
within a species (Egretta intermedia, Intermediate
Egret). COI sequences in the polytypic species separated
into pairs of divergent clusters in the NJ tree. The intraspecific
distance in the exceptional species was 8.2%, 27
fold higher than the average distance